I remember growing up my grandfather always had emergency items in his car in case it ever broke down. I thought he was crazy at the time but today I realized that he was pretty smart. So there are things that I think everyone should have in their car in case of an emergency.
Nowadays, you should always have a full charged cell phone. This is not something you should keep in your car per say but you should never leave home without it. If you are ever stranded on the side of the road, you will definitely need it.
Jumper cables are a MUST to have in your car. It happens all the time, car batteries die so you need to be prepared with jumper cables. The last thing you need after a long day of work is to walk out to your car, put the key in the ignition and all you hear is click, click, and click.
A flashlight comes in handy at night when you need to change a flat tire, jump start your car or another car or other roadside situation.
Roadside flares are used if you break down on the side of the road, usually at night. The flares will light up enough to caution other drivers that you are there on the side of the road. Place two in the front of the car and two in the back just as a precaution so you know you are completely visible.
Every car needs to have a warm blanket in the trunk. A blanket can be used for a few things. If heaven forbid you are stuck in your car overnight and the weather is cold, you have a blanket to keep warm with. A blanket can also come in handy when watching your nephew play soccer and it gets chilly out. You will have a blanket to keep you warm.Take a look here to learn more: Car Tools and Supplies for Emergency